The National Women's Soccer League (NWSL) is a professional women's soccer league, run by the United States Soccer Federation. At the top of the United States league system, it is the country's primary competition for the sport. The NWSL was established in 2012 as a successor to Women's Professional Soccer (2007–2012). The league began play in 2013 with eight teams; four of which were former members of Women's Professional Soccer. With the addition of two expansion teams in Houston and Orlando since the league's founding, it now has 10 teams based throughout the United States.
Since the league's inaugural 2013 season, a total of two clubs have claimed the NWSL Shield and two clubs have been crowned NWSL Champions. The current shield winner is Seattle Reign FC, who finished first in the 2015 season. The current champion is FC Kansas City, who won the 2014 NWSL Playoffs, and defended their championship in the 2015 NWSL Playoffs.
The NWSL season runs from April–August with each team scheduled for 24 regular season games, 12 each of home and road. At the end of the regular season, the team with the highest point total is awarded the regular season title. The four clubs with the most points from the regular season standings qualify for the NWSL playoffs, which consist of two semifinal single knockout matches (1 seed plays 4; 2 seed plays 3), with the winner of each semifinal advancing to the championship final hosted by the team with most regular season points.